Sheet metal forming press for forming flattened horns on the edges of sheet metal blanks

ABSTRACT

THE DISCLOSURE PROVIDES A SHEET METAL FORMING PRESS FOR FORMING FLATTENED HORNS ON THE EDGES OF SHEET METAL BLANKS WHICH COMPRISES A BOLSTER MOUNTED BETWEEN CENTERING SPRINGS PERMITTING THE BOLSTER TO YIELD IN A DIRECTION NORMAL TO THE DIRECTION OF PRESSING, A VERTICALLY MOVABLE DIE ADAPTED TO BE LIFTED OFF AND LOWERED ONTO SAID BOLSTER, AND A VERTICALLY MOVABLE FORMING PUNCH COOPERATING WITH SAID DIE, THE ARRANGEMENT BEING SUCH THAT THE SHEET METAL BLANK IS OPTIONALLY INTERPOSABLE BETWEEN THE FORMING PUNCH AND THE DIE OR BETWEEN THE UNDERSIDE OF THE DIE AND THE BOLSTER.

March 2, 1971 J. BIRRER 3,566,665

SHEET METAL FORMING PRESS FOR FORMING FLATTENED HORNS ON THE EDGES OFSHEET METAL BLANKS Filed April 15, 1968 3 Sheets-Sheet 1 N E? U- E? dLl- ::l I

I q- INVENTOR JOSEPH B'RRER 1 Han/w 0. g

ATTORNEY March 2, 1971 BIRRER 3,566,665

SHEET ME FORMING PRESS FOR FORMING FLA NED norms.

THE EDGES 0F SHEET METAL BLA s Filed April 15. 1968 5 Sheets-Sheet I IMH March 2, 1971 J. BIRRER 3,566,665

SHEET ME FORMING PRESS FOR FORM FLATTENED HORNS THE EDGES OF SHEET METBLANKS Filed April 15, 1968 v s Sheets-Sheet s 5 IHWHIIP l7 fi/ W I I9 KUnited States Patent O SHEET METAL FORMING PRESS FOR FORMING FLATTENEDHORNS ON THE EDGES F SHEET METAL BLANKS Joseph Birrer, Zofingen,Switzerland, assignor to Hammerle A.G., Zofingen, Switzerland Filed Apr.15, 1968, Ser. No. 721,467 Claims priority, application Austria, Apr.21, 1967, A 3,776/ 67 Int. Cl. B211 13/ 02 US. Cl. 72-404 2 ClaimsABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This inventionrelates to a sheet metal forming press for forming flattened horns onthe edges of sheet metal blanks.

SUMMARY OF THE INVENTION It is the object of the invention to provide asheet metal forming press for horning the edges of sheet metal blanksand flattening the horns in two operations without the necessity ofresetting the tools of the press.

To attain this object the present invention provides a sheet metalforming press for forming flattened horns on the edges of sheet metalblanks, which comprises a bolster mounted between centering springspermitting the bolster to yield in a direction normal to the directionof pressing; a vertically movable die adapted to be lifted oif andlowered onto said bolster, and a vertically movable forming punchcooperating with said die.

The die may be vertically movably mounted near each of its ends betweenlateral guideways and associated with rams for optionally lifting thedie off the bolster or lowerin g the die onto the bolster.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will nowbe described by way of example and with reference to the accompanyingdrawings in which:

FIG. 1 is a schematic representation of an arrangement proposed by theinvention whilst performing a first operation;

FIG. 2 is a similar view showing the same arrangement whilst performinga second operation;

FIG. 3 is a front elevation of the arrangement;

FIG. 4 is a vertical section of the arrangement according to FIG. 3, and

FIG. 5 is a vertical section of a modified arrangement according to theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of operation of apress according to the invention will first be described 'with referenceto FIGS. 1 and 2. The press comprises a baseplate 1 which is pro-3,566,665 Patented Mar. 2, 1971 vided with a recess 2 for the receptiontherein of a bolster 3. The bolster 3 is horizontally movable in therecess 2 but is urged into central position in the recess 2 by centeringsprings 4. Above the bolster 3 a die 5 is vertically movably mounted andcan be lowered to rest on the bolster 3. A V-slot 6 in the upper surfaceof the die 5 serves for forming a horn on the edge of a sheet metalblank. For this purpose the die 5 cooperates with a forming punch 7.FIG. 1 shows the forming punch 7 having descended into the V-slot 6 toform a horn on the edge of a sheet metal blank 8.

When the forming punch 7 has been raised and the sheet metal blank 8removed from the V-slot 6 the die 5 is lifted off the bolster 3 and thehorned edge of the sheet metal blank 8 is placed on the bolster 3 withthe horn pointing upwards, the free edge 9 of the horn engaging theunderside 10 of the die 5. The underside 10 of the die 5 now functionsas a pressplate when the forming punch 7 de cends into the empty V-slot6 and thus forces the die 5 downwards onto the bolster 3. The bolster 3yields laterally to the right in FIG. 2 and thus permits the horn to beflattened down on the surface of the sheet metal blank 8. If the bolster3 were unable laterally to yield, the horn could not be pressed flatbecause the upper edge9 of the horn catches on the underside 10 of thedie 5 whereas it should be free to describe an are 11 of a circle whilstbeing pressed onto the surface of the sheet metal blank 8. A rigidlyfixed bolster 3 would have the effect of subjecting the die 5, which isguided exclusively at its two ends, to such considerable lateral strainthat in practice the horn could not be properly closed. However, theability of the bolster 3 to yield by compressing the centering spring 4permits the horn to be flattened down against the surface of the sheetmetal blank 8 without the application of unduly high pressure.

Practical embodiments of the press proposed by the invention areillustratively shown in FIGS. 3, 4 and 5. A baseplate, which in thesedrawings is indicated by the reference numeral 12, carries a bolster 13which is horizontally movable between centering springs 14 provided forholding the bolster 13 in the illustrated central position. A die 15 isvertically movably mounted in laterally spaced guideways provided inportal-shaped supports 16 near each end of the die 15. The ends of thedie 15 projecting from the guiding supports rest on the rams 17 of twopneumatically operable ram cylinders 18 (FIGS. 3 and 4) which may standon the base or on separate foundations on the floor (FIG. 5). Compressedair can be admitted into each cylinder 18 through an opening 19. Eachram 17 has a spherical head 20 which bears against a cooperatingsocket-shaped surface in the end of the die 15. A forming punch 22 isadapted to descend into the V-slot 21 of the die 15 from above. Theforming punch 22 is slidably mounted in ways not shown in the drawingsand can be lowered and raised by conventional means.

The described arrangement permits sheet metal blanks to be provided withflattened horns in two operations without the need of remounting orchanging the tools. The proposed machine therefore saves labour andtime.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A sheet metal forming press for forming flattened horns on the edgesof sheet metal blanks, comprising:

(a) a bolster mounted between centering springs permitting the bolsterto yield in a direction normal to the direction of pressing;

(b) a vertically movable die adapted to be lifted off and lowered ontosaid bolster, and

(c) a vertically movable forming punch cooperating with said die, saidpress adapted to receive a sheet metal blank between the forming punchand the die or between the underside of the die and the bolster.

2. A sheet metal forming press according to claim 1, wherein the die isvertically movably mounted near each of its ends between laterallyspaced guideways and associated with ra-ms for optionally lifting thedie oh. the bolster 0r lowering the die onto the bolster.

References Cited UNITED STATES PATENTS 970,952 9/1910 Rice 72-4041,173,168 2/1916 Burditt 72-404 5 1,173,169 2/1916 Burditt 72-4042,245,642 6/1941 Bell 72-447 CHARLES W. LANHAM, Primary Examiner 10 G.P. CROSBY, Assistant Examiner U.S. Cl. X.'R. 72--447, 462

